I’ve used both and haven’t seen any difference in cleanliness. Because of this, I use powder. It makes me feel better about tossing a cardboard box instead of a plastic bottle into the trash. The powders can cause a residue if the washing machine is overpacked, so I just start the washing machine first, sprinkle the powder around and then put the clothes in.

The commercials always show people putting the detergent on the their clothes after they’ve loaded them in the washer but if you put your detergent in first and start the water and let it fill up a bit before you put the clothes in it dissolves MUCH better.

I prefer powder, because I feel like buying the liquid is essentially paying for the water that is diluting the powder… and I also feel like I have a better handle on how concentrated the soap is. But that’s just me.

The laundry rooms in our building have recently been renovated, and we now have those fancy-shmancy high efficiency Maytag machines. With those machines, you’re supposed to use HE liquid soap. I’m still using the rest of the liquid I had from before the new machines were installed, but I’ll be using the super-concentrated HE stuff when that runs out.